package a05_双指针法;

/**
 * @author: fosss
 * Date: 2023/7/29
 * Time: 13:58
 * Description:
 * 编写一个函数，其作用是将输入的字符串反转过来。输入字符串以字符数组 char[] 的形式给出。
 * 不要给另外的数组分配额外的空间，你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。
 * 你可以假设数组中的所有字符都是 ASCII 码表中的可打印字符。
 * 示例 1：
 * 输入：["h","e","l","l","o"]
 * 输出：["o","l","l","e","h"]
 * 示例 2：
 * 输入：["H","a","n","n","a","h"]
 * 输出：["h","a","n","n","a","H"]
 */
public class B02_反转字符串 {
    public static void main(String[] args) {
        String str = "hello";
        String res = reverseStr(str);
        System.out.println("res = " + res);
    }

    /**
     * 前后指针，交换字符
     */
    public static String reverseStr(String str) {
        char[] chars = str.toCharArray();
        int left = 0;
        int right = chars.length - 1;

        while (left < right) {
            char temp = chars[left];
            chars[left] = chars[right];
            chars[right] = temp;
            left++;
            right--;
        }
        return new String(chars);
    }
}














